By using the TSA style scanner on a fresco the researchers discovered another hidden artwork that went unnoticed by other techniques. (Photo : J. Bianca Jackson, Ph.D. and Dominique Martos-Levif )

For the first time a team of researchers have used the TSA style scanner on a fresco and discovered another hidden artwork underneath that went unnoticed by other techniques, according to Discovery News.

By using the terahertz spectroscopy, the technique used in airport body scanners, a postdoctoral researcher, J. Bianca Jackson of the University of Rochester, along with her colleagues studied the Italian Fresco at the Louvre Museum known as 'Trois Hommes Armes de Lances' (three men armed with lances). The team specializes in art conservation and restoration.

According to the discovery news, the team suspected that the Italian fresco had some hidden artwork underneath as it came from a 19th century art collector Giampietro Campana, who was known for reworking some of the works he obtained. Their probing helped them detect a vague face beneath the painted folds of a robe of the later fresco.

"We were amazed, and we were delighted. We could not believe our eyes as the image materialized on the screen," Jackson said in a press statement.

Initially, the team used several techniques including X ray radiography and X ray fluorescence imaging but none of these techniques proved helpful. They then used terahertz spectroscopy as this has the ability to penetrate through the materials without damaging it.

Reports according to Scientific Computing state that below the top painting of the folds of the man's tunic they discovered an eye, nose and then slowly noticed a mouth. This was a part of an ancient Roman fresco that is believed to be thousands of years old.

After getting successful results with the use of terahertz spectroscopy, the team plans to use this for scanning other artworks from the Riga Dom Cathedral in Latvia and a Neolithic site in Çatalhoyuk, Turkey.